Background

Background utilities paint an element with a theme colour, a subtle tint, the body surface or a gradient. Combine bg-{colour} with bg-opacity-* or the --ui-bg-opacity variable to fade it, and prefer the text-bg-* helpers or -emphasis text colours so contrast stays readable in light and dark mode.

1Theme colour backgrounds

bg-primary to bg-dark fill an element with a theme colour. Pair them with a readable text colour.

bg-primary

bg-secondary

bg-success

bg-danger

bg-warning

bg-info

bg-light

bg-dark

<div class="row g-2 small">
  <div class="col-6 col-md-3">
    <div class="bg-primary text-white rounded-md p-4">
      bg-primary
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-secondary text-white rounded-md p-4">
      bg-secondary
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-success text-white rounded-md p-4">
      bg-success
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-danger text-white rounded-md p-4">
      bg-danger
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-warning text-dark rounded-md p-4">
      bg-warning
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-info text-dark rounded-md p-4">
      bg-info
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-light text-dark rounded-md p-4 border">
      bg-light
    </div>
  </div>
  <div class="col-6 col-md-3">
    <div class="bg-dark text-white rounded-md p-4">
      bg-dark
    </div>
  </div>
</div>

2Subtle backgrounds

The -subtle variants are soft tints that work in light and dark mode; use the matching -emphasis text colour.

bg-primary-subtle

bg-success-subtle

bg-warning-subtle

bg-danger-subtle

bg-info-subtle

<div class="grid gap-2">
  <div class="bg-primary-subtle text-primary-emphasis rounded-lg px-4 py-2">
    bg-primary-subtle
  </div>
  <div class="bg-success-subtle text-success-emphasis rounded-lg px-4 py-2">
    bg-success-subtle
  </div>
  <div class="bg-warning-subtle text-warning-emphasis rounded-lg px-4 py-2">
    bg-warning-subtle
  </div>
  <div class="bg-danger-subtle text-danger-emphasis rounded-lg px-4 py-2">
    bg-danger-subtle
  </div>
  <div class="bg-info-subtle text-info-emphasis rounded-lg px-4 py-2">
    bg-info-subtle
  </div>
</div>

3Body backgrounds

bg-body, bg-body-secondary and bg-body-tertiary follow the page surface and adapt to colour mode.

bg-body - the page itself

bg-body-secondary - side panels

bg-body-tertiary - wells and inputs

<div class="border rounded-xl overflow-hidden">
  <div class="bg-page p-4 border-b">
    <code>bg-body</code> - the page itself
  </div>
  <div class="bg-surface-2 p-4 border-b">
    <code>bg-body-secondary</code> - side panels
  </div>
  <div class="bg-surface-3 p-4">
    <code>bg-body-tertiary</code> - wells and inputs
  </div>
</div>

4Text and background together

text-bg-{colour} sets the background and a contrasting text colour in one class.

text-bg-primary text-bg-warning text-bg-info text-bg-light text-bg-dark

<div class="flex flex-wrap gap-2">
  <span class="text-bg-primary rounded-full px-4 py-1">text-bg-primary</span> <span class="text-bg-warning rounded-full px-4 py-1">text-bg-warning</span> <span class="text-bg-info rounded-full px-4 py-1">text-bg-info</span> <span class="text-bg-light rounded-full px-4 py-1 border">text-bg-light</span> <span class="text-bg-dark rounded-full px-4 py-1">text-bg-dark</span> 
</div>

5Background opacity steps

bg-opacity-10, -25, -50, -75 and -100 fade a theme background in fixed steps.

100

<div class="flex flex-wrap gap-2">
  <div class="bg-success/100 text-white rounded-lg p-4 small">
    100
  </div>
  <div class="bg-success/75 text-white rounded-lg p-4 small">
    75
  </div>
  <div class="bg-success/50 rounded-lg p-4 small">
    50
  </div>
  <div class="bg-success/25 rounded-lg p-4 small">
    25
  </div>
  <div class="bg-success/10 rounded-lg p-4 small">
    10
  </div>
</div>

6Gradient overlay

bg-gradient adds a soft white-to-transparent gradient on top of any bg-{colour}.

bg-primary bg-gradient

Hands-on workshops

bg-dark bg-gradient

Mobile agenda

<div class="row g-2">
  <div class="col-sm-6">
    <div class="bg-primary bg-gradient text-white rounded-xl p-6">
      <div class="font-semibold">
        bg-primary bg-gradient
      </div>
      <div class="small text-white/50">
        Hands-on workshops
      </div>
    </div>
  </div>
  <div class="col-sm-6">
    <div class="bg-dark bg-gradient text-white rounded-xl p-6">
      <div class="font-semibold">
        bg-dark bg-gradient
      </div>
      <div class="small text-white/50">
        Mobile agenda
      </div>
    </div>
  </div>
</div>

7Transparent background

bg-transparent removes a fill, useful when a component's default background must disappear.

bg-white

bg-transparent

<div class="bg-surface-3 rounded-lg p-4 flex flex-wrap gap-2">
  <div class="bg-white border rounded-md px-4 py-2 small">
    bg-white
  </div>
  <div class="bg-transparent border rounded-md px-4 py-2 small">
    bg-transparent
  </div>
  <button type="button" class="btn btn-light bg-transparent border-0"><i class="bi bi-three-dots" aria-hidden="true"></i> Ghost button</button>
</div>

8Black and white

bg-black and bg-white are fixed colours that do not change with colour mode, unlike bg-body.

bg-black

bg-white

<div class="flex rounded-lg overflow-hidden border">
  <div class="bg-black text-white flex-auto p-4 text-center small">
    bg-black
  </div>
  <div class="bg-white text-black flex-auto p-4 text-center small">
    bg-white
  </div>
</div>

9Highlighted table row

Background utilities on a table cell or row mark a selection without extra CSS.

Order	Customer	Total
#INV-5563	Aria Sato	$397.07
#TX-6912	Felix Harlow	$388.12
#INV-1089	Leo Hughes	$395.18

<div class="table-responsive">
  <table class="table table-sm mb-0 align-middle">
    <thead>
      <tr>
        <th scope="col">Order</th>
        <th scope="col">Customer</th>
        <th scope="col" class="text-end">Total</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td>#INV-5563</td>
        <td>Aria Sato</td>
        <td class="text-end">$397.07</td>
      </tr>
      <tr>
        <td class="bg-primary-subtle">#TX-6912</td>
        <td class="bg-primary-subtle">Felix Harlow</td>
        <td class="bg-primary-subtle text-end font-semibold">$388.12</td>
      </tr>
      <tr>
        <td>#INV-1089</td>
        <td>Leo Hughes</td>
        <td class="text-end">$395.18</td>
      </tr>
    </tbody>
  </table>
</div>

10Feature icons on tinted circles

A subtle background with rounded-circle and fixed size gives each icon a soft colour badge.

Certificates

Recorded sessions

Hands-on workshops

<div class="row g-3">
  <div class="col-sm-4 flex gap-2 items-center">
    <span class="bg-primary-subtle text-primary rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-lightning-charge-fill" aria-hidden="true"></i></span><span class="small font-medium">Certificates</span>
  </div>
  <div class="col-sm-4 flex gap-2 items-center">
    <span class="bg-success-subtle text-success rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-shield-check" aria-hidden="true"></i></span><span class="small font-medium">Recorded sessions</span>
  </div>
  <div class="col-sm-4 flex gap-2 items-center">
    <span class="bg-danger-subtle text-danger rounded-full inline-flex items-center justify-center text-lg" style="width:44px;height:44px"><i class="bi bi-heart-fill" aria-hidden="true"></i></span><span class="small font-medium">Hands-on workshops</span>
  </div>
</div>

11Section bands

Alternating bg-body and bg-body-tertiary bands separate page sections.

Three days that change how you work

The new recorded sessions helps decisions quicker and clearer without the usual hassle.

Where great ideas meet

A bright dashboard connects time back in your day all year round.

Where great ideas meet

Our venue booking connects your work organised wherever you are.

<div class="border rounded-xl overflow-hidden">
  <section class="bg-page p-6">
    <h3 class="h6 mb-1">Three days that change how you work</h3>
    <p class="small mb-0 text-muted">The new recorded sessions helps decisions quicker and clearer without the usual hassle.</p>
  </section>
  <section class="bg-surface-3 p-6">
    <h3 class="h6 mb-1">Where great ideas meet</h3>
    <p class="small mb-0 text-muted">A bright dashboard connects time back in your day all year round.</p>
  </section>
  <section class="bg-page p-6">
    <h3 class="h6 mb-1">Where great ideas meet</h3>
    <p class="small mb-0 text-muted">Our venue booking connects your work organised wherever you are.</p>
  </section>
</div>

12Dark footer strip

bg-dark with text-white-50 and link-light builds a compact footer.

<footer class="bg-dark text-white/50 rounded-lg p-4 flex flex-col sm:flex-row justify-between gap-2 small">
  <span>&copy; Brand name 20</span> <span class="flex gap-4"><a href="#" class="link-light">Privacy</a><a href="#" class="link-light">Terms</a><a href="#" class="link-light">Contact</a></span> 
</footer>

13Alert-like message

A message strip built from bg-danger-subtle, a matching border and emphasis text.

Payment failed. This focused release turns every detail in view all year round.

<div class="bg-danger-subtle border border-danger/30 text-danger-emphasis rounded-lg p-4 flex gap-2" role="alert">
  <span class="text-lg"><i class="bi bi-exclamation-octagon-fill" aria-hidden="true"></i></span> 
  <div>
    <strong>Payment failed.</strong> <span class="small">This focused release turns every detail in view all year round.</span>
  </div>
</div>

14Background on hoverable list

List items with bg-body-tertiary for the active one; other rows stay on bg-body.

Inbox
Starred
Sent
Archive

<ul class="list-unstyled border rounded-lg mb-0 overflow-hidden" style="max-width:20rem">
  <li class="px-4 py-2 bg-page border-b"><i class="bi bi-inbox-fill" aria-hidden="true"></i> Inbox</li>
  <li class="px-4 py-2 bg-surface-3 border-b font-semibold"><i class="bi bi-star-fill" aria-hidden="true"></i> Starred</li>
  <li class="px-4 py-2 bg-page border-b"><i class="bi bi-send-fill" aria-hidden="true"></i> Sent</li>
  <li class="px-4 py-2 bg-page"><i class="bi bi-archive-fill" aria-hidden="true"></i> Archive</li>
</ul>

15Progress made from backgrounds

A bg-body-secondary track and a bg-success fill with a width utility form a simple meter.

Storage75 of 100 GB

Seats5 of 20

<div class="grid gap-4">
  <div>
    <div class="flex justify-between small mb-1">
      <span>Storage</span><span>75 of 100 GB</span>
    </div>
    <div class="bg-surface-2 rounded-full" style="height:8px">
      <div class="bg-success rounded-full h-full w-3/4">
      </div>
    </div>
  </div>
  <div>
    <div class="flex justify-between small mb-1">
      <span>Seats</span><span>5 of 20</span>
    </div>
    <div class="bg-surface-2 rounded-full" style="height:8px">
      <div class="bg-warning rounded-full h-full w-1/4">
      </div>
    </div>
  </div>
</div>

16Pricing highlight

The recommended plan gets bg-primary and white text; the others stay on bg-body-tertiary.

Basic

$6.05

Pro

$27.75

Team

$91.98

<div class="row g-2 text-center">
  <div class="col-4">
    <div class="bg-surface-3 rounded-lg p-4">
      <div class="small">
        Basic
      </div>
      <div class="text-lg font-bold">
        $6.05
      </div>
    </div>
  </div>
  <div class="col-4">
    <div class="bg-primary text-white rounded-lg p-4">
      <div class="small">
        Pro
      </div>
      <div class="text-lg font-bold">
        $27.75
      </div>
    </div>
  </div>
  <div class="col-4">
    <div class="bg-surface-3 rounded-lg p-4">
      <div class="small">
        Team
      </div>
      <div class="text-lg font-bold">
        $91.98
      </div>
    </div>
  </div>
</div>

17Colour swatches

Square swatches with bg-{colour} and a caption below, as used in a style guide.

Primary

Secondary

Success

Warning

Surface

<div class="flex flex-wrap gap-4">
  <figure class="mb-0 text-center">
    <div class="bg-primary rounded-lg" style="width:56px;height:56px">
    </div>
    <figcaption class="small mt-1">Primary</figcaption>
  </figure>
  <figure class="mb-0 text-center">
    <div class="bg-secondary rounded-lg" style="width:56px;height:56px">
    </div>
    <figcaption class="small mt-1">Secondary</figcaption>
  </figure>
  <figure class="mb-0 text-center">
    <div class="bg-success rounded-lg" style="width:56px;height:56px">
    </div>
    <figcaption class="small mt-1">Success</figcaption>
  </figure>
  <figure class="mb-0 text-center">
    <div class="bg-warning rounded-lg" style="width:56px;height:56px">
    </div>
    <figcaption class="small mt-1">Warning</figcaption>
  </figure>
  <figure class="mb-0 text-center">
    <div class="bg-surface-2 border rounded-lg" style="width:56px;height:56px">
    </div>
    <figcaption class="small mt-1">Surface</figcaption>
  </figure>
</div>

18Card header and footer tints

bg-body-tertiary on the header and footer of a card, bg-body in the middle.

Community notes for attendees

The new mobile agenda guides every detail in view on any device.

Updated 3 days ago

<div class="border rounded-lg overflow-hidden" style="max-width:24rem">
  <div class="bg-surface-3 px-4 py-2 border-b font-semibold small">
    Community notes for attendees
  </div>
  <div class="bg-page p-4 small">
    The new mobile agenda guides every detail in view on any device.
  </div>
  <div class="bg-surface-3 px-4 py-2 border-t small text-muted">
    Updated 3 days ago
  </div>
</div>

19Image scrim with bg-black

A bg-black layer at reduced --ui-bg-opacity makes white text readable over a photo.

Learn, connect and get inspired

<div class="relative rounded-xl overflow-hidden" style="max-width:28rem">
  <img src="../assets/img/wide-6.svg" alt="Three days that change how you work" class="w-full block"> 
  <div class="absolute top-0 start-0 w-full h-full bg-black flex items-center justify-center" style="--ui-bg-opacity:.45">
    <span class="text-white text-lg font-semibold text-center px-4">Learn, connect and get inspired</span> 
  </div>
</div>

20Chat bubbles

Incoming messages on bg-body-tertiary, outgoing on bg-primary, each with a rounded corner set.

Our speaker management brings time back in your day from the very first day.

The new recorded sessions turns decisions quicker and clearer without the usual hassle.

A flexible idea keeps you focused on what matters on any device.

<div class="flex flex-col gap-2" style="max-width:24rem">
  <div class="self-start bg-surface-3 rounded-xl rounded-b-none px-4 py-2 small">
    Our speaker management brings time back in your day from the very first day.
  </div>
  <div class="self-end bg-primary text-white rounded-xl rounded-b-none px-4 py-2 small">
    The new recorded sessions turns decisions quicker and clearer without the usual hassle.
  </div>
  <div class="self-start bg-surface-3 rounded-xl rounded-b-none px-4 py-2 small">
    A flexible idea keeps you focused on what matters on any device.
  </div>
</div>